Environmental Impacts of Eucalypt Plantations in the Western Gurage Watersheds, Central-South Ethiopia

Ethiopia has the largest area of eucalypt plantations in East Africa and is one of the ten pioneer countries that introduced the eucalyptus (hereafter eucalypt for singular and eucalypts for plural). In Ethiopia eucalypt plantations constitute 58% of the total plantation cover followed by Cupressus (29%), Juniperus procera (4%) and pines (2%). According to various studies establishing exotic forest plantations like eucalypts species has been under big debate over the last three decades regarding the advantages and disadvantages of growing eucalypts. The purpose of this study, therefore, is to assess the environmental impact of eucalypt plantations in Western Gurage Watersheds, which is located in Central-South Ethiopia. The specic objectives of this study were: to describe farmers’ land use practices in eucalypt plantations; to assess farmers’ perception on environmental impacts (negative and positive) of eucalypt plantations on environment; and to explore empirical literatures on the environmental cons and pos of eucalypt plantations and policy options. from three Woredas (Districts) namely Cheha, Enemorna Ener, and Eza located in were used. Systematic purposive sampling method employed by selecting with woodlots from the of each Kebeles (sub Close- and open- ended questionnaires were distributed to every fth households possessing plantations. To supplement the critical discussions with focus groups and interviews with key informant employed. The survey data were analyzed using both and To describe data acquired from focus group and key informant and logical data analysis technique were used. Data acquired from questionnaires were analyzed using Statistical Package for Social Sciences (SPSS) version Descriptive and dispersive such as frequency, percentage, mean, variance, standard deviation, p- value and correlation were employed. Empirical critical review on discussion was employed to investigate on environmental aspect of the species in the country and elsewhere. soil fertility, stream volume, microclimate change, and wildlife conict after having experienced in using the species for many decades. From multiple responses given with regard to expected eucalypts driven farmland constraints; all (100%) of the households believed that shortage of grazing land shall become more serious, there will be reduction of cattle number, productivity of enset and other crops will be decreased, and the strong traditional attachment Gurages have with enset shall get loose. About 89% of the households believed that farming transformation may take place from enset based farming system to other form. is signicant at p < 0.05. This shows that the support from experts is too small. Hence their gap is only lack of mechanization which are geared from government or other bodies and disseminated from top to down approach without the awareness and involvement of farmers. Hence the attitudes perceived by households are logically acceptable and this is critically reviewed and scientically proved in later discussion section. landholding size is about 0.52 hectare. Thus strict land use management and policy should be practiced to save this diminutive land use from eucalypts plantation conversion. About 68%, 86%, 100%, 73%, 88%, 58%, 75% and 86% of the households reported that they plant eucalypts on the farm land with crops, farm boundary, degraded lands (gully sides), previously cultivated land, around the course of streams, close to settlement, along roadside, and on grazing lands respectively. This shows that most of the sites are not considered as ideal sites except on degraded lands (gully sides) and along road sides. Their opportunity to use ideal sites is already overshadowed by its multidimensional and short term benet. Households have enough on the various aspects of eucalypt plantation and it is clearly seen in their perceptions. Thus about 81%, 94%, 98%, 95%, 97%, 96% and 93% of the households agreed on statements such as: eucalypt tree expansion can change a fertile land to wasteland; planting eucalypt on farmland can increase land degradation problem; fast growing trees like eucalypt are water sacking plants; avoiding litters fallen from eucalypt can reduce soil degradation and improve the regeneration of undergrowth; it is important to use animal dung and crop residue as soil fertilizers rather than using it for fuel wood; eucalypt tree cover can balance local climate with similar cases to other plants; and it is possible to reduce the adverse impact of eucalypt by thinning and planting it in rugged lands respectively. The aggregate P-Value is < .00001. The result is signicant at p < .05. The value of R is -1. This is a strong negative correlation, which means that high X variable scores go with low Y variable scores (and vice versa). Surprisingly farmers are real farm managers in their indigenous knowledge. Farmers know what agronomists did not know. Farmers need what they have not.


Introduction
Ethiopia has the largest area of eucalypt plantations in East Africa and is one of the ten pioneer countries that introduced the eucalyptus (hereafter eucalypt for singular and eucalypts for plural) (Getahun 2002). In Ethiopia eucalypt plantations constitute 58% of the total plantation cover followed by Cupressus (29%), Juniperus procera (4%) and pines (2%) (Teketay, 2000). According to various studies (Lugo, 1992;Senbeta, 1998;Calder, 2002; establishing exotic forest plantations like eucalypts species has been under big debate over the last three decades regarding the advantages and disadvantages of growing eucalypts. Some of the commonly mentioned advantages include quick provision of bene ts associated with fast growth, short rotation plantations for production of fuel wood and timber. Under proper management they are good source of forage for bees (honey production), can produce ber for pulp and paper industries under relatively short rotation, can grow adequately in a wide range of ecological conditions and sites among others (Jagger and Pender, 2000;Teketay, 2000;Brooker, 2002;Calder, 2002).
On the contrary, despite these bene ts, eucalypts have been said to have their disadvantages (FAO, 1988;Jagger and Pender, 2000;Teketay, 2000). These alleged disadvantages include consumption of much ground water associated with its high growth rate. They may not provide good soil protection against erosion and may not provide good habitats and supports biodiversity. Its leaf litter has adverse effects on soil humus.
In Ethiopia, such critiques have led to develop an opinion differences among academic circles and policy makers. Eucalypts' impacts and responses at different sites are complex and may require substantial research and adequate information before conclusive arguments can be made. Given these scenarios, conclusive decisions on eucalypts will likely be a major debate in the years to come. The curse-blessing debate concerning eucalypts is not a new phenomenon. But, it is now more charged with a mixture of fact and ction (Negash, 1990 andTeketay, 2000). Most criticisms are based on a range of technical, ecological and socioeconomic arguments (FAO, 1988). According to Davidson (1989), many of the criticisms are unfair, biased, nationalistic or emotional. He noted that the criticisms would apply equally to other exotic trees planted in many countries; they are not peculiar to the eucalypts. On the one Gurage Zone is divided by four drainage basins, namely Awash, Rift Valley, Blate and Omo-Gibe (Sahle et al., 2018). With the exception of minor deviations at local level, the streams in the Zone have a dendrite drainage pattern. The direction of ow of the streams may vary depending upon orientation of local relief at micro level. However, all the major streams ultimately drain to west and south-west/east ward following the general inclination of the slope direction of the Zone. The Western Gurage Watersheds drain to Omo-Gibe Basin and covers large areas. In the western parts of Gurage, several rivers and streams are available, which drains from East to West to Gibe River. The major rivers are Wabe, Winike, Megecha, Rebu, Zizat, Gogare and Dire. These rivers have several numbers of streams, which emerge from the Gurage Mountains and join at different locations. The rivers Winike, Gogare and Derie are the main rivers next to Wabe River, and together cover an area of 173,476 ha (Fig. 1).
From these, the main watershed is Winike, which includes Megecha and Zizat rivers and covers an area of 117, 030 ha. The Gogare and Drie watersheds cover an area of 30,739 and 25,707 ha, respectively.
The ve districts of Gurage Zone, i.e. Eza, Cheha, Gumer, Geta and Enemorna Ener, are found in these watersheds. These watersheds areas share almost all characteristics of Gurage Zone. These watersheds were selected due to their dense population and high coverage of eucalypts under expansion.

Secondary Data
To get clear understanding of the concept such as eucalypts' expansion, eucalypts' completion, income diversi cation, livelihood support and the like, secondary data from journals, theses, and reports were reviewed critically. In this part exclusion and inclusion approach, selecting and retrieving the appropriate and recent literatures were made. Thereafter the nal report ( ndings) was analyzed and synthesized to show and ll the research gap.

Sampling method, procedure and distribution
The study area, Gurage Zone has thirteen Woredas (Districts) with 1,279,646 populations (CSA, 2007). For the purpose of the study, samples from three Woredas located within Western Watersheds of Gurage Zone were collected. The selected Woredas were Cheha, Enemorna Ener, and Eza. These Woredas were purposefully selected due to large coverage of the watersheds, dramatic expansion of eucalypts farming and hereby high eucalypts pole production, incidences of serious competition of eucalypts with other uses, and the presences of road accessibility for data collection. Thus, these Woredas were representatives of eucalypt plantation activities since eucalypt growing and land holding system are more or less similar in the other parts of the Zone.
To get primary data about the study, systematic purposive sampling method was employed. Thus, after selecting households with eucalypt woodlots from the list of each Woreda's Kebeles (the lowest administrative unit), closed and open ended questionnaires were distributed to every 5th households possessing eucalypt plantations. The main reason for selecting this sampling method is to avoid the inclusion of non-eucalypt tree farmers and to keep the validity of the representative samples (to cover large villages within the Kebeles).

Sample size determination
From the total 71792 household population living in the three woredas (CSA, 2007), 383 household respondents were selected using the following formula by assuming con dence level at 95% and margin of error) at 5%. The sampling formula is shown as follow (Cothari, 2004).  To supplement the information; critical observation, discussions with focus groups and key informant interviews were employed. Individual farm households whose were age were greater than 70 years old and knowledgeable persons to discuss on the eucalypts plantations, reasons for expansion, conversion of crop land to eucalypts woodlot and others were selected. Thereafter, three focus group discussions with farm households were conducted in the three districts. Each group included six up to eight members. The discussions were guided by facilitator during which group members were encouraged to talk freely on raised topics. Key informant interviews were conducted with well experienced individual farm households and experts in each district. Hence a total of nine key informants were selected from nine sample Kebeles of the three districts. Important professional key informant interviews were employed with six agricultural and natural resources experts from the three districts (two experts from each). Interviews with Agricultural Development Agents (DAs) and kebele chairpersons were employed. In each district individual interviews and informal communications with eucalypt pole traders and middle men were conducted. From all the focus group discussions and interviews valuable and detail information were gathered by principal researcher and assistants with the help of voice recording devise and smart phone camera. After transcribing the audio documents in to written words, translation to English was performed. Thereafter, all the information investigated were included in the appropriate result and discussion parts of the research. The discussions were supported by various actual eld photos.

Method of Data Analysis
The survey data were analyzed using both qualitative and quantitative techniques. To describe data acquired from critical observations, focus group discussions, key informants' interviews, critical and logical qualitative data analysis technique were used. Data acquired from questionnaires were analyzed using Statistical Package for Social Sciences (SPSS) version 20. Descriptive and dispersive statistics such as frequency, percentage, mean, variance, standard deviation, p-value and correlation were employed.

Households' awareness on environmental impacts of eucalypts
Households in the study area have enough knowledge on environmental aspects of eucalypts after having many decades of experiences in using the species for various needs. They have given more emphasis to socioeconomic importance of the species and its environmental externalities gained less attention particularly in using multidimensional management options. As depicted in Table 3.1 below, about 87% of the households reported that they have heard messages about environmental impacts of eucalypt plantations. Only 13% of the rest did not hear any message towards such impacts. The three Woredas responses were proportional perceptions as to the pooled result. Those respondents who did not hear any message about the environmental impacts of the species were young farmers who were more attracted by its economic rewards and had short span experience in planting the species. Households practiced eucalypts tree planting as environmental conservation mechanisms in their private possessions. As described in Table 3.2 below, 84% of the households practiced environmental conservation using eucalypts planting particularly on the gully sides and erosion prone areas. The rest 16% of them did not practice eucalypts for this purpose. As clearly observed by researcher most gully sides and eroded lands of private possessions are becoming covered with eucalypts, whereas communal lands with similar problems are covered with Grevillea robusta, pines, corpuses lusitanica, and juniperus procera through government launched participatory watershed management.  Yes  126  88  124  89  85  85  335  87   No  17  12  16  11  15  15  48  13 Source: Field Survey (2017). As can be seen in Table 3.3 below, 78% of the households believed that population growth should not be controlled to alleviate environmental degradation. Their reason as reported in focus group and key informant discussion is that population growth is not aggravating such problem since farmers care for their lands. The other 22% of the respondents reported that population growth have impact on environmental degradation claiming that further crops and eucalypts planting shall leads to land exhaustion and degradation. The mean and standard deviation values are 127.67 and 125.34 respectively. The P-Value is 0.02082. The result is signi cant at p < 0.05. As clearly observed by researcher, population growth is not a major cause for land degradation in the study area, rather lack of appropriate land use management is a curtail problem. As reported by Woldetsadik (2003) more people more tree situation of Boserupian Theory is working in the Gurage area and thus land degradation and population growth have nothing to do with negative relationships. That is why eucalypts expansion in the study area is seen as environmental recovery since it covered extensive areas including gully sides and badlands. It has substituted forest degradation/deforestation. Hence eucalypt is seen as a blessing not a curse species in Gurage area, no matter how its competition with farm and grazing lands is threatening the area.

Households' expected farmland constraints
As depicted in Table 3.4 below, from multiple responses given with regards to expected eucalypts driven farmland constraints; all (100%) of the households believed that shortage of grazing land shall become more serious, there will be reduction of cattle number as a result of its conversion to eucalypt woodlots, productivity of enset and other crops will be decreased, and the strong traditional attachment Gurages have with enset shall get loose. About 89% of the households believed that farming transformation may take place from enset based farming system to other form. The other 23% of them believed that there will be serious surface run off. The mean and standard deviation values are 85.33 and 78.16 respectively. The P-Value is 0.00007. The result is signi cant at p < 0.05. All the perceptions understood by households are logical and only ideal land uses planning and management will balance all these constraints which are very serious as far as the Gurage cultural, livelihood and environmental settings are concerned.

Land use practice of eucalypts plantations
As depicted in Table 3.5, households who spent 2 to 5, 6 to 10, 11 to 20 and 21 to 30 minutes of average walking distance from eucalypt stands to the nearby grazing lands accounted 31%, 22%, 26%, and 21% respectively. Households who spent 2 to 5, 6 to 10, 11 to 20 and 21 to 30 minutes of average walking distance from eucalypt stands to the nearby farmland accounted 38%, 28%, 27%, and 7% respectively. Households who spent 2 to 5, 6 to 10, 11 to 20 and 21 to 30 minutes of average walking distance from eucalypt stands to the nearby stream accounted 42%, 46%, 7%, and 5% respectively. Households who spent 2 to 5, 6 to 10, 11 to 20 and 21 to 30 minutes of average walking distance from eucalypt stands to the horticulture accounted 8%, 6%, 40%, and 46% respectively.
Households who spent 2 to 5, 6 to 10, 11 to 20 and 21 to 30 minutes of average walking distance from eucalypt stands to homestead accounted 5%, 10%, 37%, and 48% respectively. Households who spent 2 to 5, 6 t0 10, 11 to 20 and 21 to 30 minutes of average walking distance from eucalypt stands to road accounted 36%, 46%, 8%, and 10% respectively. and horticulture and near to grazing land, farmland, stream and road. Since the average landholding size of the area is about 0.52 hectare, the species is competing to the latter land uses rst and its nal destination is to the former land uses. Unless urgent land use management is applied by the government and other bodies, the area in the near future will be transformed to eucalypt landscapes topography much higher than ever in the land use history of the area.
The nally destiny will result in total food insecurity and alteration of environmental and cultural settings.

The perceived Environmental changes
Households know all the multidimensional environmental changes perceived as a result of eucalypt plantation in their localities through experience and they are con dential to describe the indicators accordingly. As indicated in Table 3.6 below, all the households (100%) reported that eucalypts have multidimensional effect. Thus from the given indicators, as depicted in Table 3.7 below, 39%, 20%, 5% 5% and 2% of the households reported that there is major decrease, minor decrease, no change, minor increase and major increase respectively towards soil erosion. Hence collectively about 74% of them are optimists and seen the species as a conservation safeguard. About 38%, 46% and 16%, of the households reported that there is major decrease, minor decrease and no change respectively towards soil fertility. None of them reported that there is minor increase and major increase observed in soil fertility. Here collectively 84% of them seen it as an agent of soil degradation.
About 62%, 29% and 9% of the households reported that there is major decrease, minor decrease and no change respectively towards stream ow volume.
Here about 91% of the households have perceived a decreasing situation of stream ow. Hence eucalypt died up or reduced the volume of smaller tributaries and springs. None of them reported that there is minor increase and major increase observed in stream ow volume. About 34% and 66% of the households reported that there is minor increase and major increase respectively towards competition with croplands. Hence all of them perceived its serious competition with croplands. None of them reported that there is major decrease, minor decrease and no change observed in competition with croplands. About 66%, 8%, 12%, 5% and 9% of the households reported that there is major decrease, minor decrease, no change, minor increase and major increase respectively towards gully formation. Hence collectively 74% of them perceived a decreasing situation of gully formation. That is why most gully sides in private landholdings are covered with eucalypt plantations as a safeguarding strategy.
About 70%, 29% and 1% of the households reported that there is major decrease, minor decrease and no change respectively towards undergrowth. Hence almost all of them perceived a decreasing situation of undergrowth. None of them reported that there is minor increase and major increase observed in under growth. About 15% and 85% of the households reported that there is minor increase and major increase respectively towards presence of birds. Here all of them perceived that eucalypt is serving as a home to birds. None of them reported that there is major decrease, minor decrease and no change observed in presence of birds. About 79%, 16% and 5% of the households reported that there is major increase, minor increase and no change respectively towards presence of wild animals. Hence collectively 95% of them perceived that there is an increasing situation in presence of wild animals. Eucalypt is used as a hiding and transitional agent after wild animals cross over the forests or bushlands. None of them reported that there is major decrease and minor decrease observed in wild animals. That is why the area is known for wild animals' con ict and thereby domestic animals and crops are attacking by them much higher than ever as reported by focus groups and key informants.
There is a mean value of 104.6, 65, 20, 78.63 and 114.8 for major decrease, minor decrease, no change, minor increase and major increase respectively for all indicators. There is a standard deviation value of 110.9, 65, 20.96, 88.71 and 150.4 for major decrease, minor decrease, no change, minor increase and major increase respectively for all indicators. The aggregate P-Value is 0.037277. The result is signi cant at p < 0 0.05. Thus households were intrinsically following the perceived environmental changes, however, land diminution and short term valuable reward gained from its product overshadowed their opportunity to apply the optimum land use alternatives.  As can be indicated in Table 3.8 below, 52% and the remaining 48% of the households reported that there are crops which resist and do not resist negative effect of eucalypts. The former stated crops such as wheat, maize, pees and bean, and most perennials resist the effects when planted in the nearby areas.
The later reported that all crops are susceptible and its effect is not selective and clearly seen in the quantity and quality of production of annuals and perennials. As shown in Table 3.9 below, all households reported that there are dried streams, rivers, and springs due to eucalypt tree plantations in their localities. As observed by the researcher the volume of the known rivers in the study area are decreased dramatically particularly in dry seasons. Even in rainy seasons rivers which were known for their over ow out of their natural channels were decreased their volume due to the decrease in the volumes of tributaries and disappearance of smaller springs and through ow (seeping).
As shown in Table 3.10 below, from multiple responses given towards changes observed in the forest cover after the expansion of eucalypts since the last 20 years, 100%, 95%, 20% and 6% of the households reported that eucalypt tree cover has increased, natural forest has increased, other plantation forests have increased and natural forest has decreased respectively. None of them reported that natural forest has disappeared. The mean and standard deviation values are 169.4 and 168.96 respectively. The P-Value is < 0.00001. The result is signi cant at p < 0.05. As clearly observed from the gures, eucalypts' cover increment and its substitution in fuel wood and construction resulted in the regeneration of forests and thereby there is increasing trend of the overall coverage. As clearly revealed in Table 3.11 below, 100%, 100%, 17%, 79% and 45% of the households perceived that stream ows are decreased or dried, farmlands are fragmented, runoffs are increased, yields are declined and gullies and rills are created respectively. The mean and standard deviation values are 260.8 and 124.49 respectively. The P-Value is < 0.00001. The result is signi cant at p < 0.05. The perception on incidence of runoffs as seen is minimal and about 83% of the households believed that eucalypt has nothing to do with it and in contrary they plant it to reduce runoff.   Source: Field Survey (2017).
As described in Table 3.13 below, from the given multiple responses all the households preferred planting eucalypts in upslope, down slope, degraded and marginal areas. They do not preferred planting close to streams and farmlands, and over grazing areas. However, practically they are not practicing this assumption as a result of unsuitable nature of the former locations in harvesting and transportation. Thus they forced to plant in the later locations which is scienti cally not advisable due to serious land use competition with crop, grazing and wet lands.  Upslope areas  143  100  140  100  100  100  383  100   Down slope areas  143  100  140  100  100  100  383  100   Degraded areas  143  100  140  100  100  100  383  100   Marginal areas  143  100  140  100  100  100  383  100 Close to streams 3.5. Impacts of Eucalypt plantations on the land use system As depicted in Table 3.14 below, from multiple responses given about land use pattern, all (100%) households devoted their land under enset, vegetables, cereal crops, eucalypts, grazing and grasslands. Lands under orchards, chat, and coffee accounted 92%. Bushland and degraded areas constituted 40% and 25% respectively. The mean and standard deviation values are 321.8 and 107.55 respectively. The P-Value is < 0.00001. The result is signi cant at p < 0.05.
The small possession of bushlands and grazing lands are due to the conversion of these lands to eucalypt woodlots.   As shown in Table 3.17 below, 7% and 93% of the households removed and did not remove respectively for eucalypt woodlots for agricultural use. The lesser number of households who removed the species for agricultural use is attributable for the non-affordability of the households to use tractors for this purpose. As reported by focus groups, those households who afforded using tractors are relatively wealthy ones either by themselves or by remittance support. Households perceived yield risk level of farming types. As shown in Table 3.18 below, 39%, 26%, 27% and 8% of households reported that enset crop is highly risky, risky, moderately risky and not risky respectively in yield. About 36%, 39%, 25% and 0% of households reported that annual foods crop are highly risky, risky, moderately risky and not risky respectively in yield. Similar risk levels are followed by vegetables, cash crops and mixed cropping. About 94% and 6% of households reported that eucalypt woodlots are not risky and moderately risky respectively in yield. None of them reported that it is highly risky and risky. Similar case is followed by fruit trees. The aggregate mean and standard deviation values are 95.75, 75.34 respectively. The P-Value is 0.000069. The result is signi cant at p < 0.05. Hence the yield risk level is less perceived in eucalypt woodlots and fruit trees. This might be attributable for the perennial nature of these two products and less requirement of farm management. Eucalypt woodlots insusceptibility for most risks is already scienti cally justi ed. Its completion with the former farming types aggravated risk level in yield. One of farmers' attractions of planting more eucalypts is also attributable for its less riskiness.

Discussion
Eucalypts have been blamed for many evils, including the drying-up of water courses, adverse effects on nutrient cycling and soil properties, the suppression of other vegetation and erosion. These are serious accusation made by authors from many countries and they have even overshadowed the bene ts of the eucalypts (Okia, 2009).
No single fact should be taken as su cient evidence to promote or to discourage the planting of the eucalypts, though the results from a large number of studies taken together may yield valid generalizations (Jagger and Pender, 2000; FAO, 1988; Davidson, 1985). There is no question that trees in general and the eucalypts in particular utilize large amounts of water and nutrients, but the returns that can be realized in terms of biomass production per unit of input must also be considered.
Similarly, Davidson (1989) argues that the criticisms would equally apply to other exotic trees planted in many countries, not just the eucalypts. Therefore, any balanced argument should compare the nutrient depletion to the outputs produced for each unit of water and nutrient consumed than the absolute amount consumed in isolation. In the controversy over eucalypts there has been a tendency for the negative and positive aspects of the genus to be highlighted. Some of these are brie y discussed in the following subsections.

Water use by Eucalypts
Eucalypt has taken the vast area of the world and raising fears over water resources and eco On the contrary, eucalypt is water e cient tree species than other crops though eucalypt is perceived as high water consumer by some environmentalist (Davidson, 1989;Teshome, 2007;FAO, 1988). Most eucalypt species averagely use 785 liter of water to produce 1kg of biomass (Davidson, 1989).
To the extreme, it has been thought that eucalypt species consume a lot of water more than any other tree species and agricultural crops. However, this is far from reality. They have greater water use e ciency (i.e. they consume less water per unit of biomass produced) than most agricultural crops, conifers, acacias and broad-leaved tree species (Table 3.21). To produce one unit of woody matter young trees require between 300 and 500 units of water, but as they get older their e ciency decreases and more water per unit of wood is needed (Teketay, 2000). In fact, use of water is proportional to the amount of biomass produced (wood, branches, twigs, leaves, owers, fruits, etc.), and the relatively high water consumption is consistent with their high growth rate and biomass production.
In arid regions, water is limited and plants with deep spreading roots take most water while plants with shallow roots may be stunted or unable to survive. In low rainfall areas, eucalypt species may suppress other plants by competing for water, but this is unlikely to occur in areas of high rainfall (Davidson, 1989). If the planting is not well planned, it may reduce the groundwater level and thereby affect water supplies of the local people. Davidson (1989) also reported that at Nekemte (Western Ethiopia) with annual rainfall of 2158 mm, E. saligna and E. grandis could produce 46.6 m 3 /ha/yr without drawing on water reserves (rainfall only) compared to 16.4, 16, 12.4 m 3 /ha/yr biomass production for the coniferous, acacia, and broadleaf species, respectively. These gures reveal that for the same amount of water consumed, eucalypt produces higher amount of biomass, which is economically pro table and acceptable.
In swampy areas, the groundwater level is near or at the surface, and some species of eucalypts have been used to drain the water away by drawing it up through the roots. E. globulus is useful for this purpose. Mosquito breeding swampy areas can sometimes be controlled in this way. Drainage removes swamps which provide a habitat for mosquito larvae, thereby reducing the risk of malaria. This method has been used in various parts of Ethiopia (Teketay, 2000).
Many studies reported that water use in eucalypt is comparable to other tree species. There are some cases where afforestation with eucalypts (or other tree species) has lead to reduced water run-off and supply of streams or changes in water table levels, especially in regions with limited rainfall. However, in many well documented cases eucalypt plantations do not have any signi cant negative impacts on hydrology. A key nding of many experiments revealed that eucalypt is highly effective in regulating its water consumption relative to available supplies and regulates its growth accordingly. Based on numerous comparisons that have been made between the potential hydrological impacts of eucalypt and other tree species, it is not expected that the eucalypt trials planted under these permits would be any more impactful on local hydrology than planting other fast growing trees species.
Study conducted in the Ethiopian highlands, Pohjonen and Pukkala (1990) reported that E. globulus converted energy and available water into biomass more e ciently when compared with exotic coniferous tree species. Therefore, although some species of eucalypts may consume more water than the indigenous forest or other plantations, which may lead to reduced water yield and leaves less available water for other crops growing in association with the tree, it is more e cient in terms of converting water into biomass.

Effects on soil fertility
The effects of the eucalypts on soils have been studied in several countries over many years (Kindu etal., 2006, Poore & Fries, 1985. Most of the concerns related to effects on soil quality deal with the depletion of nutrients. Moreover, a number of studies indicated that changes in some soil properties are in uenced by tree species (Poore & Fries, 1985).
Studies by Dessie and Erkossa (2011), Kidanu (2004), Chanie (2013) argued that eucalypts decreases soil nutrients within 20m distance from the trees. The comparison study of eucalypts with mixed plantation has revealed that eucalypt has three times more ne root biomass in surface soil which indicated that planting crops in association and adjacent to eucalypts should be avoided (Gindaba, 2003). However, eucalypt species exceptionally can extend the nutrient cycling deep to ground soil where other trees and crop could not access that much depth (Hailu et al., 2003).
The wetland conversion study has indicated that there is signi cant difference between wetlands and converted land to dominantly eucalypts by reducing major nutrients from the converted land which is eucalypts (Mekonnen and Aticho, 2011). Similarly, Soil nutrient and carbon pool under eucalypts is lower than the mixed plantation (Gindaba, 2003). In addition to the above, as reported by Chanie (2013), the soil under eucalypts becomes water repellent and the perceptions of the local farmers agreed with the experimental ndings by reducing the crop productivity of the land. On contrast to the above, Tadele and Teketay (2014) has found that the maize dry matter production and grain yield planted on cleared felled eucalypts stand are signi cantly higher than adjacent eld. According to Hailu et al. (2003) eucalypt does not over exploit the soil than the traditional fuel usage such as litter and cow dung collection. Similarly, the study has indicated that due to non browsed characteristics of eucalypts than other fodder tree, it is well tted for soil protection purposes if it is incorporated with avoidance of liter and bark collection in overgrazing practiced places. Generally, there is lack of clear scienti c evidence that shows eucalypts' impact on soil nutrient that lead to soil degradation.
Although it is blamed to extracts substantial amount of nutrients and compete with crops, at the same time eucalypts impoverish the soil. It could be legitimate to raise such concern under poor management where there is lack of species-site match (Davidson, 1989;FAO, 1988;Nigatu and Michelsen, 1993 and 1994).
Eucalypt copes with such variability through a root system that has intimate contact with the large volume of soil. With the extension of its root deep into the soil, given its high degree of adaptability, it extracts nutrients outside the realm of crops feeding zone. That is why its nutrient requirement is signi cantly lower than that of many agricultural crops (Moges, 1998(Moges, , 2010. As a result, the species ourishes with sustainable high yield without fertilizer on red ash and degraded land. Further, eucalypt is not a natural forest that has little disturbance. If it were a closed system, nutrients would have been recycled from decomposing litter back to the tree and increase the nutrient bank (Teshome, 2009). But, eucalypt is an open system and nutrients are removed from the site when the stem, leaves and bark are harvested for various uses 1994). This means that the nutrient capital of the soil could be diminished. Therefore, the secret lies in nutrient mining. This is equally true for crops under poor management. Under viable environment, soil nutrient levels can be improved through sound management without the carrying capacity of land being overstretched.
Very few comparative studies have been made in Ethiopia on soil nutrients among plantations of different species including eucalypt species and the adjacent natural forests Nigatu and Michelsen, 1994;Michelsen et al., 1996;Alemu, 1998). These studies have shown that plantation stands of fast growing exotics such as E. globulus, E. grandis, E. saligna, Cupressus lusitanica and P. patula had lower nutrient contents than soils of the adjacent natural forest. This seems logical as they are fast growing, thereby drain, and consume more nutrients from the soil. Eucalypt species have high demand for nutrients, but this incomparable with other tree species and much lower than agricultural crops. Teshome (2009) pointed out that the nutrient consumption of fast growing species like eucalypt species need to be well studied before wrong conclusion and recommendation is being made.

Issues on soil erosion
Soil erosion is among the most important surface processes that result in land degradation in the tropics. Trees can in uence soil erosion mainly through intercepting rainfall which dissipates its kinetic energy. The rain drops that are intercepted eventually fall to the soil surface with reduced erosive energy, depending on the size and orientation of the leaves. Large leaves produce larger size droplets which have greater impact on the soil. Accordingly, erosive energy of rain under the crowns would be least for Casuarina spp. with Acacia spp. (e.g. A. auriculiformis) and narrow-leaved eucalypts (e.g. E. camaldulensis) occupying the mid-range and the broad-leaved eucalypts (e.g. E. globulus) at the top of the range for the eucalypts (Jagger and Pender, 2000).
Consequently Jagger and Pender (2000) reported that there is no evidence to single out the eucalypts for special criticism with regard to soil erosion. It has been hypothesized; however, that-long term exposure to allelo-chemicals may result in increased risk off soil erosion, which may have implications for sustainable land use over time (Jagger and Pender, 2003).
Eucalypt has been found to have impacts on topsoil retention and soil erosion (Dessie and Erkossa, 2011;Sunder, 1993;Poore and Fries, 1985). Some studies have concluded that eucalypt can worsen soil erosion as an indirect result of frequent disturbance from repeated harvesting (Poore and Fries, 1985). Others argue that eucalypt plantations can help control soil erosion on sloped or degraded sites, but their e cacy depends on environmental factors such as intensity of rainfall, soil condition, slope and the presence of ground vegetation and litter cover. Though few Ethiopia-speci c case studies exist, the limited evidence available suggests that eucalypt may be an ineffective choice for erosion control (Sunder, 1993). Rather, eucalypt trees are generally expected to lead to an increase in soil loss due to the reduced understory cover in densely planted eucalypt areas (Poore and Fries, 1985).
The litter which accumulates under most eucalypt plantations can help to form a protective barrier against erosion, but in many places the litter is collected as fuel or removed to reduce re hazard. For instance, the depth of the accumulated litter under eucalypt stands in Shashemene Munessa Forest Project area was found to be on average 20-30 cm (Teshome, 2009). However, under eucalypt stands around Addis Ababa and very big towns, the accumulation of litter is very low as a result of human and livestock disturbances. People take away most of the litter and cattle and foot tra c compact the soil. If the litter is left on the site uncollected, it would have been incorporated into the soil system to slow down runoff and improve in ltration, and substantial amount of nutrients may pass to the soil system, thereby improving soil fertility (Teshome, 2009). However, as a result of litter collection, the ground under the trees is left bare and the soil is exposed to erosion. Therefore, litter should be allowed to accumulate on the sites, particularly on sites that are easily eroded.
A realistic assessment of each area to be planted is needed to decide whether erosion will be a serious problem, and if so, whether it can be controlled. Some places may not be suitable for plantation establishment. Eucalypt plantations on steep slopes can provide effective erosion control if careful techniques such as contour planting are used (Teketay, 2000). The root systems of selected species for catchment protection in uence the soil binding capacity and as a result reduce erosion. E. globulus, for instance, has a strong tap root and good lateral root system that makes it very reputable species for catchment protection (Teketay, 2000;Teshome, 2009).
In regard to soil erosion by water under trees, there is no evidence to single out eucalypts for special criticism. Erosive resistance (physical characteristics) of soils is more important than crop management and crop management is more important than the type of tree crop. Since, in nearly every example where the litter is removed, erosion increases substantially, it is important to focus more on ground cover and ground level activities (cultivation, compaction by foot tra c, livestock grazing, trampling, and harvesting/logging damage rather than on the species of trees planted. On erosion-prone slopes it is better to use a periodic, partial harvesting system based on cutting of trees on lines around the contour or on removal of small patches in a mosaic pattern (Teketay, 2000; Jagger and Pender, 2003 ).

Allelopathic effect
Allelopathy is the release of chemicals from leaves or litter that inhibit the germination or growth of other plant species (FAO, 1985), and consequently reduce the output of crops. Allelopathic effect of eucalypt is among the issues dominating the agroforestry literature. Allelopathic exudates from eucalypt tree components have shown an inhibiting effect on undergrowth vegetation regeneration and growth (Poore & Fries, 1985).
Most of the studies put forward as "evidence" for eucalypts being strongly allelopathic involve laboratory studies of extracts on germination of seeds or early growth of potted plants which may not accurately represent eld conditions. Soil bioassay studies have been carried out with three agricultural crops: chickpea (Cicer arietinum), tef (Eragrostis tef) and durum wheat (Triticumturgidum) under laboratory and eld conditions in the Ethiopian highlands. According to the ndings, bioactive compounds from the decomposing litter of E. globulus did not affect the test crop seed germination nor root growth. However, a litter extract with 5% dry matter concentration signi cantly hindered germination and root growth of the tested agricultural crops. On a farm eld experiment, declining barley yield was observed near a E. globulus plantation (Jagger and Pender, 2005).
Results evidently vary across a wide spectrum of conditions from humid, fertile sites to dry, infertile ones. The magnitude of the negative effects may be in uenced by rainfall. Although it is likely that allelo-chemicals do accumulate in the soil, they are highly soluble and rainfall is likely to leach them out and the effects of Allelopathy are thus likely negatively correlated with rainfall. It has been noted that allelopathic effects are more severe in low rainfall regions prone to soil erosion than in drier regions. However, the hampering effect on growth of understory or adjacent intercropped crops may more often be the result of strong competition for water and nutrients than Allelopathy. Farmers in the highlands of Ethiopia linked this effect to competition for water and nutrients (Jagger and Pender, 2005).
The potential allelopathic effect of E.camaldulensis, Cupressus lusitanica, E. globulus, and E. saligna on seed germination and seedling growth was investigated with four crops: chickpea, maize, pea and teff (Eragrostis teff Zucc.) (Limenih and Michelsen, 1993). The results revealed that aqueous leaf extracts of all the tree species signi cantly reduced both germination and radical growth of the majority of the crops. It has been shown that the shoot and root dry weight increase of the crops was signi cantly reduced after ten weeks treatment with leaf extracts.
Allelo-chemicals can effect germination and growth of plants through interference in cell division, energy metabolism, nutrient uptake etc. Fetene and Habtemariam, 1995;Teshome, 2009;Yirdaw and Luukkanen, 2003). In this regard, eucalypt has toxic allelo-chemicals that consist of phenolic acids, tannins, and avonoids (Yirdaw and Luukkanen, 2003). When realized into the soil, these inhibit other plants and play a role in shaping plant communities. For instance, leaf decomposition product from eucalypt is shown to suppressed germination and growth of chickpea, eld pea, maize, and tef  while it exerted an antibiotic effect on soil microorganisms (Limenih and Bongers, 2010).
However, concentration matters. For instance, allelo-chemicals from decomposed eucalypts' litter in high rainfall areas did not accumulate in su cient concentration to affect seed germination and root growth of crops. Different strength of water extract from leaves of eucalypts did not delay the onset of germination and seedling growth of Olea (Yirdaw and Luukkanen, 2003; Limenih and Bongers, 2010; . In fact, positive results have also been reported concerning the interaction of eucalypts with other plants (Kidanu et al., 2005). The lack of susceptibility of certain crops and the regeneration of other species suggest that eucalypts provide some bene t rather harm. Again, it is not only eucalypts but other exotic tree species such as Grevillea robusta which is a common feature in Ethiopia has allelopathic effects on most agricultural crops (Teshome, 2009).
However, in Ethiopia, little attention has been given to Allelopathy as determinant of crop production and productivity Chanie, 2009) and plant community structure (Senbeta, 1998;Moges, 1998;Yirdaw, 2002;Limenih, 2004). Therefore, empirical information is needed to resolve such negative effect. Until then, Allelopathy can be minimized with sound management through compatible crops based on proper eucalypt species' site selection.

Competition with nearby vegetation
One of the criticisms associated with eucalyptus is that it prohibits the establishment of understory plant species. Eucalypt is usually taller than other plants of equal age. This has determined the amount of gap that would be available for sunlight to penetrate through its canopy. When planted at high density, the shade created has adverse in uences on the understory environment (Zerga, 2015). The consequence could be vegetation free surface. The dense stands not only affect the growth of colonizing woody species, but also nearby crops given the added competition for water and nutrients. Then, yields from crops close to eucalypts may not be as good as those farther from the edge. Then, it is not eucalypts rather the lack of sound management that is to blame (Teketay, 2000). On the other hand, not all eucalypt species cast heavy shadow to discourage understory plants. Some even cast less shade than broad-leaved trees because they have often narrow, patchy crowns and leaves positioned downwards on the twigs (Yirdaw and Luukkanen. 2003).
As a case in point, several eucalypt plantations in different agro-ecological zones showed richness of herbaceous plant species than under adjacent natural forest. Further, the less dense plantations harbored more regenerated indigenous woody tree species than high dense eucalypts stands (Yirdaw, 2001;Senbeta and Teketay, 2001;Michelsen et al., 1996;. This indicates that an inverse relationship exists between eucalypts density and diversity of the regenerated species. In relation to economic crop, wheat production was not affected by eucalypts on heavy clay soil (Kidanu, et al., 2005).
When used as shade tree for coffee, its cup quality was acceptable as that within the indigenous forest (Shiferaw and Tadesse, 2010).
Because of shading and competition for water, the yields from agricultural crops close to eucalypt plantations are sometimes not as good as they are further away from the edge (Teketay, 2000). However, some eucalypt species cast less shade than other broadleaved trees because their leaves are held vertically downwards on the twigs and their crowns are often narrow. It is widely accepted that shelterbelts increase crop yields. On the other hand, the study made by Onyewotu et al. (1994) on the competitive effects between a E.camaldulensis shelterbelt and an adjacent millet (Pennisetum typhoides) crop indicated that the yield of the crop grown very close to the belt was reduced because of competition with the trees for light, soil moisture and nutrients, and shading. On the other hand, the results indicated that the yield of millet grown adjacent to the shelterbelt increased substantially. It is worthwhile to note that in eucalypt species the shade is characteristically patchy because the leaves usually hang downwards, indicating that shading is not a major problem.
However, not all eucalypts' cast shade which is heavy enough to discourage ground vegetation or understory shrubs, and shading can be adjusted by varying the density of the trees. There are complex interactions between light and water requirements of different trees that make generalizations di cult. Certainly there are several species of trees with larger leaves than the eucalypts, thus they cast more shade.

Scarcity of wild animals
Ethiopia has diverse wildlife of world importance. Yet, there has been the erosion of these resources due to the destruction of their habitat from introduction of agriculture, recurrent drought, war and con ict. Among others, the unpalatability of eucalypt leaves is supposed to reduce the number of wildlife and livestock in an area. Due to its competitive nature, eucalypt is considered not to provide adequate fodder to wildlife (FAO, 1988;Negash, 1999). There is thus the debate should be on whether wildlife would remain in their newly established eucalypts habitat or not.
In the rst place, eucalypt is never established in natural forests that harbor wildlife. If there were some in the landscape, the destruction of the habitat might have forced them to migrates; obviously prior to eucalypts. Then, it is di cult to imagine that degraded area, barren and treeless landscape could have provided the suitable habitat to wildlife.
Instead, they would migrate due to deforestation of the original forest. The subjective perception of the species is in the absence of objective studies which demonstrate that eucalypt plantations host lower wildlife population compared to a barren landscape that is now rehabilitated with indigenous species under a similar setting. The objective reality, however, is that with the establishment of eucalypts, the canopy has provided shade for the emergence of undergrowth vegetation and the regeneration of indigenous trees. Now that they have a suitable habitat, some of the wildlife has returned. As a case in point the scenic evergreen eucalypts plantation on Entoto Mountain that surrounds Addis Ababa hosts diverse wildlife even with large human population around and has become a prime destination to tourists (Senbeta and Teketay, 2001;.
Further, the ower of eucalypts that produces abundant pollen and nectar has been essential in the life cycles of many insects and birds. These are important in the pollination of crops and bees provide additional bene t through production of honey. This has become a lucrative business to many rural communities.
Under sound management similar plantations could exploit such potential without adverse effect on the ecology or crops. Palatable leguminous trees, shrubs, forages, pastures, and grasses can also be established under appropriate sound management. Then, such rehabilitated areas can be made favorable to wildlife instead of the categorical blame of eucalypts as restriction to their proliferation (Davidson, 1989 and1995;FAO, 1988;Pohjonen and Pukkala, 1988 and 1990).
The unpalatability of most species to browsing and grazing animals (FAO, 1988;Davidson, 1989;Pohjonen, 1989;Turnbull, 1999) and incapability of providing adequate food and habitat for wildlife (FAO 1988;Negash, 1999;Teketay, 2000) can thus reduce wildlife in an area. However, this problem can be alleviated by establishing mosaics of plantations, natural forests, pastures, grasslands and croplands. It is important to note that the biodiversity of a natural forest and that of eucalypt plantations are not comparable. The natural ecosystems are very diverse, whilst the biodiversity of eucalypt plantations is limited.
Mammals and birds that used to live in natural forests can be encouraged to return to a forest replanted with a mixture of exotic species by leaving open spaces occasionally, and allowing undergrowth to remain here and there.

Climate change effect
One of the criticisms against eucalypt plantations is that they may cause a change in the local climate. This is because of their very high evapotranspiration rate, which may lead to a lower water table. This high rate of soil water loss is claimed adversely to affect local rainfall levels, resulting in possible deserti cation of a given area. But others argue that the contribution of the land mass to the hydrologic cycle is small compared with that of the oceans (Lee, 1980). On the other hand, the mere presence of a forest in a certain area does not necessarily affect the occurrence of rainfall in that area.
Eucalypt trees do an excellent job of sequestering CO 2 because they e ciently store carbon in all their live biomass. Especially in the tropics, where sun and rain are abundant, extremely high conversion of CO 2 occurs in the biomass. With such high e ciency, it is only natural that eucalypt trees grow quickly and with high productivity. Eucalypt is an e cient biomass producer; it can produce more biomass than many other tree species. It is known that carbon sequestration is proportional to biomass production. Therefore, Eucalypt plantations can play an important role in generating additional revenues from carbon trade.

Effects on plant species diversity
One of the major criticisms that have been debated over years among the scholars concerning eucalypt is its impact on ora of the area. On contrary to the above, eucalypt has potential in encouraging the recruitment, establishment and successions of native species, which promote biodiversity improvement . Regeneration of Junipersprocera on previously eucalypts plantation was also possible at Entoto, Ethiopia, which has shown wrong believes that planting other trees after harvesting eucalypts is not possible (Woldu, 1998;Senbeta and Teketay, 2001;. Mostly, eucalypt is feared for ecological hazardous and ecosystem destructor, but eucalypt is an important tree in fostering ecosystem serving as conservation Plantation stands of eucalypts and other tree species have been shown to foster or catalyze the regeneration of native woody species under their canopy provided that they are established close to seed sources and protected from human and livestock disturbances, thereby enhancing biodiversity (Senbeta, 1998;Moges, 1998;Teketay, 2000).
The studies made by Mihretu (1992) and Kidane (1998) indicated that there is a good natural regeneration of J. procera under E. globulus plantations at Entoto hills in Addis Ababa. The juniper has grown effectively on the eroded areas competing well with the eucalypt trees Similarly, the studies made by Senbeta (1998) and Moges (1998)  there is now increasing knowledge of the ecological pros and cons of eucalypts better than before and most importantly the biodiversity impacts are clearly disproved. Rather eucalypts are considered as a foster species that nurse the rapid re-colonization of native species when planted on barren and degraded lands.

Policy Options
As Janz and Persoon (2002) expressed, there are serious shortcomings in the supply and use of information needed for policy-making in the forestry sectors, particularly those of developing countries. It should be underlined that, for a successful forest policy process, it is often necessary to know, among several other things, more about plantations and their role for rural communities. There is a general prejudice against forestry, particularly against fast-growing trees plantation, as compared to agriculture (Cossalter and Pye-Smith, 2003).
The current policy issue regarding eucalyptus planting in Ethiopia seems not in the favor of the species. There is no encouraging concern in the country to raise eucalyptus seedlings from government nurseries and distribute them for smallholder farmers. The views of policy makers are largely less favorable to eucalyptus. Owning to its importance, the policy practice of discouraging and in some cases banning planting of eucalyptus by farmers need rethinking from the side of the policy makers. Taking into account the dwindling natural forests in Ethiopia, it would be necessary to pass legislation to require that almost all charcoal, poles and rewood be derived from plantations of fast-growing species such as eucalyptus, to prevent further loss of natural forests (Turnbull, 1999).
There is a need for care when comparing policy and actual practice, because stated intentions in policy documents sometimes bear no relation with how policies are interpreted and applied (Sithole, 2002). In another concern, interventions to support market prices for the products of tree growing and to ensure producers' access to markets may be as effective as or more effective than subsidies. Agricultural policies should be complementary to tree growing.
Subsidies for credit, price supports and incentives, including measures affecting land and tree tenure, should be seen in parallel to both agricultural crops and tree growing like eucalypts by farmers in order to avoid policy measures that likely to distort decisions against one at the expense of the other (FAO, 1981).
Actually, the poor management should be blamed rather than eucalypts. All things are always changing; and our way of thinking should change with the rapidly changing conditions of our world. At the face of heightened climate risks, the harmonization of forestry and agriculture policy unquestionably helps combat food insecurity and poverty. In reference to eucalypts, as elaborated, the evidence so far reveals that the species will continue to gure prominently in the life of both rural and urban people (Moges, 2010). Hence, its justi able place in the development policy of the country means that individuals and communities can be encourage to accelerate the establishment of commercial exotic plantation and indigenous forest that will not contravene the ecology.

Conclusion And Recommendations
Eucalypt has become the most preferred species for planting by farmers due to its economic bene t and huge demand of fuel wood and construction materials. In Ethiopia Eucalypt plantations constitute 58% of the total plantation followed by Cupressus (29%), Juniperus procera (4%) and pines (2%).
Apparently, in recent years, planting of eucalypts has been faced controversies and critiques based on ecological and socio-economic arguments in Ethiopia and elsewhere. Hence eucalypts have been blamed for many evils, including the drying-up of water courses, adverse effects on nutrient cycling and soil properties, the suppression of other vegetation, allelopathic effect and erosion. Whether these criticisms are based on fact or arise from deliberate bias or even lack of accurate information may be questioned. Most of the reports available on eucalypts are in favor of planting it. The paradox mostly results from the poor management rather than its biological characteristics. Therefore, the debate on eucalypts under the pretext of concern for indigenous forests is 'a storm in a tea cup' and must not widen the urgent attention. In this regard, farmers are not blind to its claimed negative ecological and agricultural impact. They have utilized the knowledge and experience through time to ensure sound eucalypts production. Then, their primary focus must be the acquisition of the knowledge on what motivates farmers to embrace eucalypts. With the insight and wisdom gained, the effort should be to win them not against their will but against their background.
In the study area, households use their land holding size for different uses per hectare in different decades. From different uses eucalypts and enset ranked rst and second in the three decades of 1990s, 2000s and 2010s by accounting 13%, 36% and 45%; and 16%, 24% and 20% respectively. Grazing, grass and degraded lands taken the next share of land holding size. All others are possessed very small holdings. Hence their former sizes were reduced as a result of their conversion to eucalypt plantations. The average landholding size is about 0.52 hectare. Thus strict land use management and policy should be practiced to save this diminutive land use from eucalypts plantation conversion. About 68%, 86%, 100%, 73%, 88%, 58%, 75% and 86% of the households reported that they plant eucalypts on the farm land with crops, farm boundary, degraded lands (gully sides), previously cultivated land, around the course of streams, close to settlement, along roadside, and on grazing lands respectively. This shows that most of the sites are not considered as ideal sites except on degraded lands (gully sides) and along road sides. Their opportunity to use ideal sites is already overshadowed by its multidimensional and short term bene t.
Households have enough awareness on the various aspects of eucalypt plantation and it is clearly seen in their perceptions. Thus about 81%, 94%, 98%, 95%, 97%, 96% and 93% of the households agreed on statements such as: eucalypt tree expansion can change a fertile land to wasteland; planting eucalypt on farmland can increase land degradation problem; fast growing trees like eucalypt are water sacking plants; avoiding litters fallen from eucalypt can reduce soil degradation and improve the regeneration of undergrowth; it is important to use animal dung and crop residue as soil fertilizers rather than using it for fuel wood; eucalypt tree cover can balance local climate with similar cases to other plants; and it is possible to reduce the adverse impact of eucalypt by thinning and planting it in rugged lands respectively. The aggregate P-Value is < .00001. The result is signi cant at p < .05. The value of R is -1. This is a strong negative correlation, which means that high X variable scores go with low Y variable scores (and vice versa). Surprisingly farmers are real farm managers in their indigenous knowledge. Farmers know what agronomists did not know. Farmers need what they have not.
Collectively most of the households perceived that eucalypts have good trends in microclimate change over twenty years period. Eucalypts' cover increment and its substitution in fuel wood and construction resulted in the regeneration of forests and thereby increasing trend of the overall coverage. Thus about 100%, 100%, 17%, 79% and 45% of the households perceived that stream ows are decreased or dried, farmlands are fragmented, runoffs are increased, yields are declined and gullies and rills are created respectively. The perception on incidence of runoffs is minimal and about 83% of the households believed that eucalypt has nothing to do with it unless the litters are cleared for fuel wood purpose and in contrary they plant it to reduce runoff.
About 70%, 29% and 1% of the households reported that there is major decrease, minor decrease and no change respectively towards stream ow volume.
About 34% and 66% of the households reported that there is minor increase and major increase respectively towards competition with croplands. About 9%, 12%, 5%, 66% and 8% of the households reported that there is major decrease, minor decrease, no change, minor increase and major increase respectively towards under growth. About 39%, 20%, 5% 5% and 2% of the households reported that there is major decrease, minor decrease, no change, minor increase and major increase respectively towards soil erosion. About 38%, 46% and 16%, of the households reported that there is major decrease, minor decrease and no change respectively towards soil fertility. About 15% and 85% of the households reported that there is minor increase and major increase respectively towards presence of birds. About 5%, 16% and 79% of the households reported that there is no change, minor increase and major increase respectively towards presence of wild animals.
Thus households were intrinsically following the perceived environmental changes, however, land diminution and short term valuable reward gained from its product overshadowed their opportunity to apply the optimum land use alternatives.
About 7% and 93% of the households removed and did not remove respectively for eucalypt woodlots for agricultural use. The lesser number of households who removed the species for agricultural use is attributable for the non-affordability of the households to use tractors for this purpose. As reported by focus groups and key informants, those households who afforded using tractors are relatively wealthy ones either by themselves or by remittance support. Thus, based on the ndings of the study, the following recommendations were forwarded.
instead of blaming eucalypt species itself, there should be an intrinsic criticism to management of the species by all stake holders in order to involve in the ideal management of land use allocation; farmlands, grasslands, grazing lands and wetlands should be kept from eucalypt plantations to save these land uses from its adverse externalities; there should be substitutions for income generations of eucalypt poles by improved horticultural crops in order to curb its environmental and cultural drawbacks; farmers, government, NGOs and other stakeholders have to involve in implementation of appropriate species and site selection, tinning, and blending of the species in order to minimize its adverse impacts; district and zonal agricultural and natural resources experts have to give continuous training to farmers on the appropriate land use practices; there should be a community service on best pilot land use practitioner farmers at the beginning and these best practices should be scaled up to all farmers through time; participatory in depth research should be conducted on environmental aspect of eucalypts to reach at nal decision and act accordingly towards the optimum plantation; and there should be a speci c policy rati cation and enacting towards eucalypt plantations in order to use it at optimum land use practices in private and communal lands.
Location map of the Western Watersheds of Gurage Zone. Note: The designations employed and the presentation of the material on this map do not imply the expression of any opinion whatsoever on the part of Research Square concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. This map has been provided by the authors.  The average walking distance from eucalypt stands to different land uses in minutes.

Figure 4
The indicators of perceived environmental changes.

Figure 5
Changes observed in the forest cover after the expansion of eucalypts since the last 20 years.

Figure 6
Negative changes perceived due to eucalypts.

Figure 7
Perceived trend of trend of micro climate change due to eucalypts over time.

Figure 8
Land use pattern used by households. Land holding size for different uses per hectare in different decades Figure 10 Location of eucalypts plantation.

Figure 11
Yield risk level of farming types Figure 12 Households' attitudes/statements on eucalypt plantations.

Figure 13
Status of Woreda agricultural experts' visit to households' farm.